200hp M20B25 BUILD

[BMWE30200HP]

Hi guys ive heard alot of things about not beeing able to build a 200hp m20b25 on a budget.

parts used:

late model 320i block 80mm bore
731 head
m52b25 crankshaft (out of an E46)
m50 main and rod bearings
CXracing 135mm h beam con rods
IE new billet 272 camshaft
IE stainless steel intake and exhaust valves
single valve springs (m20b25 uses dual springs)
lightened flywheel (7 lb)
stock m20b20 clutch
Chinese made headers (bought on amazon)
E36 aluminum radiator
g plus oil cooler
toyota celica 84.5mm cast pistons


electronics:
megasquirt ms2
ford explorer v6 ignition coil pack
ford explore v6 NGK 8mm sparkplug wires
340cc injectors
crankshaft position sensor




the engine ended up having 11:1 compression and block was bored out to 84.5mm total cc was a little over 2.5l



check out my IG for pics. ( havent figured out how to upload).


https://www.instagram.com/juanfergomezdlt/


any question please ask

[digger]

did you achieve the goal?

that isn't really a budget build by my definition its effectively a full rebuild, maybe in Ecuador things are cheap. for that amount of effort i think nearer to 250bhp is possible

[ELVA164]

Why would you go single valve spring?

[BMWE30200HP]

did you achieve the goal?

that isn't really a budget build by my definition its effectively a full rebuild, maybe in Ecuador things are cheap. for that amount of effort i think nearer to 250bhp is possible

well i did do a full rbuild but not buying the stock pistons that are roughlly $800 or going forged that cost around $1200 helps alot and using good used parts goes a long way. right now the car is dynoed at 187hp but with a bit more tuning and better fuel i could easily hit 200. regular fuel here is supposedly 87 octane but with the octane meter i have it read 84 and premium is "91" but actually closer to 89. and maybe the word budget is slightly loose but i am using of the shelf part no crazy custom pistons o specific reground cams here in ecuador we dont have that tech so its not possible.

- - - Updated - - -

Why would you go single valve spring?

used the single valve sprig because it less load on the engine it like removing the ps pump but without losing the luxury.

oh and here in ecuador parts are roughly 2-3 times more expensive then in the states like an e46 crank with STD. rod and main journals costs about $900 so its not that cheap.

[superj]

but you are not worried about floating the valves with single springs?

[ELVA164]

Haha, that's not at all like removing power steering. Oh boy.

[Geoffzie]

I think the valve spring rating is primarily a function of engine RPM range ... not necessarily HP. He didn't say what RPM the 187HP was developed at ... so what IS the suggested max. RPM range for the stock single valve springs?

He DID use stainless steel valves .. which would be slightly heavier. Might have been a good idea to use heavier springs.

[ELVA164]

The eta redline is either 4,800 or 5,200rpm depending on production date. Unless he went long-stroke he isn't staying there.

[BMWE30200HP]

I think the valve spring rating is primarily a function of engine RPM range ... not necessarily HP. He didn't say what RPM the 187HP was developed at ... so what IS the suggested max. RPM range for the stock single valve springs?

He DID use stainless steel valves .. which would be slightly heavier. Might have been a good idea to use heavier springs.

the SS valves are actually lighter then stock and when you but a higher rate spring the cranks needs nor for to open the valve so if you can get away with using lighter valves you can use lighter springs as well. when i was building the engine i also built one with stock 325i valves for the 885 head and that engne at 7k rpm did have valve float and piston to valve clearence was to small so we had some issues but my engine with the same spring and cam with the SS valves revs to 7k without issues.


and the 187hp was at 6.1k rpm and 173 ft lb. @ 4.3k rpm